John Mayer and three members of the Grateful Dead will be playing New York's Madison Square Garden under the name Dead & Company on Oct. 31. Turns out, Mayer only recently become a fan of the group.

Mayer tells Billboard that it all started in 2011 when he heard "Althea" on a Pandora station and was immediately struck. From there, he started listening to the Dead on satellite radio. "I feel like my generation also has SiriusXM to thank," he said. "The Grateful Dead station on Sirius is its own experience, especially if you drive. If you live in Los Angeles, it's such a brilliant way to score the commute."

Because he was only 17 when the band broke up following Jerry Garcia's 1995 death, Mayer acknowledged that his Dead experience is different from the traditional fan, because he only knows them on a musical level. "I represent this generation of listener who didn't go to those shows," he explained. "There was no sensory bonus for the music. I don't know how much a T-shirt was or who made the best chili. I don't have any of that fan show-going experience, so I really discovered the music on a totally pure level. ... I didn't come it from the experience of 'a friend brought me to a Dead concert in 1987 and I had the time of my life.' I came at it, like, this music transports me to a place in my own imagination."

Rumors that Mayer was going to embark on a project with the Grateful Dead first surfaced in April, when he was spotted "in a rehearsal-like setting with select members of the group." Bob Weir, Mickey Hart and Bill Kreutzmann will join Mayer and Allman Brothers bassist Oteil Burbridge for the Halloween concert. To prepare, Mayer said that he's been practicing "four to five hours a day. It’s been 15 years since the last time I sat in the room and just tried to get better at playing. It's what I've called Grateful Dead University. It's like a study abroad -- a totally immersive course and a real self-driven scholarship."

See the Grateful Dead and Other Rockers in the Top 100 Albums of the '70s

Watch Bob Weir Play ‘Me and My Uncle’ with RatDog at Mountain Jam